Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Stand with feet shoulder-width apart, holding a barbell or EZ curl bar with an underhand grip, hands 6-8 inches apart. Keep elbows close to your torso, knees slightly bent. Exhale, curl the bar upwards by flexing your elbows, keeping upper arms stationary. Lift until biceps are fully contracted. Pause, then inhale as you slowly lower the bar back to the start, maintaining control. Repeat.
Use a narrow, comfortable grip. Keep elbows tucked and stationary. Perform slow, controlled movements. Maintain a neutral spine and engaged core. Avoid elbow lockout at the bottom.
MuscleTrain is actively being built. If something looks broken, or you have a suggestion, let us know — it really helps shape the app.